Attachment plug



G. w. GOODRIDGE ATTACHMENT PLUG Filed May 12. 1924 July 7, 1925.

ATTORW Patented July 7, 1925.

UNITED STATES PATENT OFFICE.

GILBERT w. GOODRIDGE, F FAIRFIELD, CONNECTICUT, ASSIGNOR TO THE BRYANTELECTRIC COMPANY, or BRIDGEPOBT, CONNECTICUT, A CORPORATIQN or con-NECTICUT.

ATTACHMENT PLUG.

Application filed May 12, 1924. Serial ire/7125271 To all whom it mayconcern:

Be it known that .I, GILBERT W. Goon- RIDGE, a citizen of the UnitedStates of America, residing at Fairfield, in the county of Fairfield andState of Connectiout, have invented certain new and useful Improvementsin Attachment Plugs, of whichthe following is a specification.

My invention relates to attachment plugs, and particularly to aseparable attachment plug. The object of my invention is to improve theconstruction of the body of the plug and its associated contacts/incertain particulars hereinafter described or shown in the accompanyingdrawings, in

which Fig. 1 is a view showing the body of the I plug in side elevation,and the cap detached and in perspective;

Fig. 2 is an axial section through the plug showing the cap and 'bodymembers ene s Fig. 3 is a section through the body, of-

the plug, partially in section and at right angles to the section shownin Fig. 2;

Fig. 4 is an interior plan of the end button of the plug body;

Fig. 5 is an interior plan of the insulating block of the plug body,showing the contacts in position; and

Fig. 6 is a detached perspective of the contacts of the lug body.

In the form' liere shown the plug comprises separable cap and bodyelements a and Z) respectively. The cap is in general of standard type,comprising an insulating base apertured at 16 to accommodate a cable'endand provided on its inner face with ledges upon which are seated thewire terminal plates 17 and 18. Integral blades 19 and 20 project fromthe terminal plates ang serve to engage the contacts of the plug bo Thebody I) of the plug comprises a main insulating block 21 and acooperating end button 22 independent thereof. The button 22 is securedin position by a stud or rivet 23, the head of which is molded into theblock 21 while its projecting shank passes through an axial hole in thebutton 22, and its spread end 24 serves as the center contact of theplug body.

The screw shell contact 25 sleeves upon the block 21 and abuts against apenpheral shoulder 26, while its diaphragm 27 overlies the endof theblock 21 and is engaged and secured against same by the button 22 whenthe latter is riveted in position. In order to prevent relative rotationof the screw shell and block, tongues 28 offset recesses 29' from thediaphragm 27 enter formed in the end of the block.

The spring metal contacts 30 and 31 of the plug body which receive theblades 19' firmly against the diaphragm by the butv ton 22 when thelatter is riveted in position. In order to insure a good electricalconnection between the screw shell and contact, and also to aid inholding the contact in position in the well 32, the base 36 of thecontact is slotted to form a tongue 38 which is offset from the base 36and projects slightly toward the button 22. The pressure of the buttonagainst the tongue 38 not only forces the-base 36 more firmly againstthe diaphragm 27, but it also forces the contact 30 toward the wall ofthe well [32' against which the blade of the cap rests in insertedposition, and thus nsures a better contact therewith.

A barrier rib 39 located adjacent the base flange 36 of contact 30, andaccommodated in a corresponding recess 40 in the inner face of thebutton 22, spaces the contact 30, and also the screw shell web 27, fromthe stem of the center contact rivet 23.

Electrical connection between the contact 31 and the center contactrivet 23 is established by the offset base flange 41 of the contact. Theflange is apertured at 42 to snugly fit the shank of the stud 23, and 1sheld firmly against the end of the block 21 by the button 22 when thelatter is riveted in place. The hole 42 may be of slightly less diameterthan the stem of the rlvet and the flange slotted to form a tongue 43.T1115 n y P mi s the stud to pass through the hole, the tongue 43 beings rung for this purpose, but the pressure of the button 22 against thetongue forces the latter strongly a ainst the stud and thus establishesgoo electrical connection therewith. The spring efiort of the tonguealso aids in pressing the contact 31 against the inserted blade of thecap.

To facilitate the entry of the cap blades into the guideways 34 and 35which lead to the contact chambers 32 and 33, the outer or cap end ofthe block 21 is dished at 44. The concave surface thus afforded centersthe cap with respect to the plug body when held in alignment therewith.The blades are thus aligned with the guideways'34 and 35.

It will be observed that the plug body requires but a single securingmember to hold all of the parts together, and that that securing memberforms the center contact member of the plug. The parts are all rugged,inexpensive to manufacture and assemble, and good electrical connectionis maintained not only between the screw shell and center contact andtheir related receptacle contacts, but also the receptacle contacts arespring pressed into such position that they make good electricalconnection with the inserted blades of the cooperating cap.

With the understandin that the construction shown may be varied inproportion and shape of parts, and in many details of constructionwithout departing from the thoughts which underlie my invention, Iclaimv 1. An attachment plug comprising a block of insulating materialpierced to afford a pair of contact chambers opening to one end of theblock, and apair of guideways opening from said chambers to the oppositeend of the block, a center contact stud carried by the block andprojecting from one end thereof at a point between said chambers, aninsulating button secured by said stud against one end of the block, anda spring metal contact arranged in one of the chambers of the block andhaving a base flange engaged between said button and block, said baseflange being apertured to accommodate said stud and having a tonguedisplaced into good electrical contact with said stud by the pressure ofthe end button there against in the assembled condition of the parts.

2. An attachment plug comprising a block of insulating material piercedto afford a pair of contact chambers opening to one end of the block anda air of guideways opening from said cham ers to the opposite end of theblock, a center contact stud carried by the block and rojecting from oneend thereof at a point Between said chambers, an insulating buttonsecured by said stud against one end of the block, a screw shell sidecontact sleeved on the block and having an end diaphragm partiallyoverlying one end thereof and engaged by the'button, a flange offsetfrom said disphragin and engaging a recess in the end of the block tohold the screw shell against rotation on the block, and a spring metalcontact arranged in one of the chambers of the block and passing throughthe screw shell diaphragm, said contact having a base flangeengaged bythe button and pressed thereby against the dia phragm to establish goodelectrical connection therewith in the assembled condition of the parts.

3. An attachment plug comprising a block of insulating material piercedto afford a pair of contact chambers opening to one end of the block anda pair ofguideways opening from said chambers to the opposite end of theblock, a center contact stud carried by the block and projecting fromone end thereof at a point between said chambers, an insulating buttonsecured by said stud against one end of the block, a screw shell sidecontact sleeved on the block and having an end diaphragm partiallyoverlying one end thereof and engaged by the button, a flange offsetfrom said diaphragm and engaging a recess in the end of the block tohold the screw shell against rotation on the block, and a spring metalcontact arranged in one of the chambers of the block and passing throughthe screw shell diaphragm, said contact having a base'flange engaged bythe button and pressed thereby against the diaphragm to establish goodelectrical connection therewith in the assembled condition of the parts,said base flange having a portion thereof offset toward the button toinsure a good electrical contact between the base flange and the screwshell diaphragm, and also to increase the effective engagement. betweenthe contact and the blade of an associated cap.

In testimony whereof I have signed my name to this specification.

GILBERT W. GOODRIDGE.

